Also check the VG ratio in the liquid, as VG increases the sweetness. Some prefer all pg, the throat hit is better, but light on vapor production. I like a 80/20 mix, nice throat hit, good vapor, or try going totally pg and see if the sweetness is reduced. Also ask the supplier if they add additional sweetness, if so and it's mixed to order ask them to cut back on it or you may want to try your hand at mixing your own liquid.
I have some straight PG and it's sweet to me too. Most of my vapes are a mix around 50/50. Haven't got brave enough to try my own. Thanks for suggestions.